Flat-Panel Fridge

From BBC News | Technology | World Edition:

A new approach to refrigeration and cooling could make for high-efficiency, portable, and quiet refrigerators in the future. The method works by repeatedly applying an electric field to long molecules called polar polymers. Advocates of the method say it will achieve a ten-fold increase of efficiency over conventional cooling. The technology could also be applied to flexible applications such as self-cooling clothing. Such a scheme could take a bite out of the 15% of total energy consumption in the UK that is dedicated to refrigeration. Conventional refrigeration and air conditioning work by compressing a refrigerant, which grows cold as it is allowed to rapidly expand. The refrigerant is then circulated around to remove heat from fridges or air that is then used for cooling. While environmentally unfriendly chemicals have been removed from air conditioners and refrigerators, the process is still noisy and relatively inefficient. The new method instead takes its cooling power from the ordering and disordering of the polymers, which are distributed in a thin film just a millionth of a metre thick. In an electric field, the molecules spontaneously line up, creating heat. Removing the field causes the polymers to cool down again as a result of the electrocaloric effect. This energy-from-order is evidenced when stretching and releasing a rubber band; stretching it lines up the mess of its constituent long molecules, warming it up. If the temperature at which these transitions occur is near the temperature of the desired cooling, the effect can be exploited. Though the temperature range of the new work is still too high to result in ice-cold beer, it has achieved a cooling of 12 C (22 F), showing that polar polymers might just do the trick.

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